All the families claim their babies were born without eyes or had microscopic eye deformities, where the eyes are the size of pinpricks, because the mothers were exposed to garden fungicide sprays or crop pesticides.
The Delaware court judgment will open the floodgates for thousands of litigants who suffered personal injury in the UK but want to take advantage of the more generous payouts in the American courts. American courts also have wider rules for forcing companies to disclose documents.
The UK parents, in what has become known as the "eyeless babies case" say a garden fungicide and crop spray containing Benlate, manufactured by the American company, DuPont, contained harmful chemicals that injured foetuses. Some mothers are part-time gardeners who spent part of their pregnancies tending their gardens and vegetable patches. The fungicide spray, now withdrawn from over-the-counter sale, was designed to prevent mould and fungus on fruits and vegetables.
The families took years to find a possible connection between the fungicides and pesticides and their children's deformities. Some families tried to bring legal action in the English and Scottish courts, in the jurisdiction of the alleged injury, but ran into difficulties.
Peter Attenborough from Newburgh in Fife, whose son Jonathan, 8, was born with microscopic eyes, failed in his attempt to have his case brought in Scotland.
"DuPont objected to the Scottish Legal Aid Board," he said. "We were told they had submitted two `not insubstantial booklets' to the Scottish Legal Aid Board outlining their objections. If we wanted to see them we had to sign a waiver saying that we wouldn't use the information in the main action. We refused."
Mr Attenborough is a spokesman for the 40 Scottish families affected by the Delaware decision.
Another case brought by an English family, Chris and Maggie and Bourne, advised by the London law firm Russell Jones & Walker, has been given the go-ahead in West Virginia on 25 October, the first case to be brought against DuPont by a UK family. DuPont denies liability in all cases.
Maggie and Chris Bourne, from Frinton, Essex, did not even know it was physically possible babies could be born without eyes. "After Andrew was born the nurse took him away," said Mrs Bourne. "When she came back she said she was sorry but he had been born without eyes. What she was saying was so shocking I didn't believe her. It sounded so alien." For 12 years, since the birth of Andrew, who has to attend a special school in Kent, the Bournes have been trying to find out what had caused the condition, known as anophthalmia.
Five years ago they discovered American families had brought cases against DuPont for a similar condition allegedly caused by exposure to a DuPont chemical agricultural spray. They won legal aid in this country but their barrister said there would be problems of evidence in a UK court. Then they started trying to have the case heard in America.
"I gardened a lot when I was pregnant with Andrew," said Mrs Bourne. "I used the spray to stop my vegetables and fruit getting fungus and mould."
The Bournes' action is a test case for many other families in the UK intending to sue DuPont. "All actions rest on us which is quite a responsibility for us and for Andrew," his mother said.
A previous decision by a Delaware court had found in favour of DuPont, which had blocked the families' case on the basis that Britain would be a more appropriate forum to hear the case because that was were the "alleged activities took place".
But the Delaware Appellate Court ruled: "The fact that the plaintiffs are foreign does not deprive them of the presumption that their choice of forum should be respected."
Alan Care, litigation executive at Russell Jones & Walker, said: "We have fought this case for years and the Delaware court's decision is a significant breakthrough."
His firm represents 100 families who believe their children's deformities are linked to DuPont chemicals.